Mirroring and Disaster Recovery

Products

• IDMS
• IDMS - Database

Issue/Introduction

DASD Mirroring for disaster recovery talks about the use of Sync or Async options. Is there any IDMS related advice about this for use with IDMS backups and recovery?

Environment

Release: All supported releases.

Resolution

Some DASD manufacturers appear to be using these terms to describe different modes of what falls under the category of manual recovery for IDMS. The "Sync" version appears to be similar to what would be described as using hot back-ups and perhaps using a duplex exit to keep a backup version of the system in sync with the production database at all times. Async is more similar to keeping a backup copy of the database in sync with the most recent physical backup taken when all activity against the database had been paused, to provide a clean recovery point. 

The use of these facilities (Sync / ASync) appears to be using DASD-based technology to create backups of the files instead of using the IDMS utilities.

IDMS Technical Support has no official opinion on the use of DASD Sync / ASync for recovery. The only methods of backup and recovery for which support is offered are the approaches using the actual IDMS utilities. So if a site relies on the DASD Sync or ASync backups for Disaster Recovery instead of using the IDMS utilities, and something goes wrong, IDMS Technical Support would not be able to help recover from that. The DASD support team would need to provide assistance with that.